Design Optimization of a Bidirectional Microswimming Robot Using Giant Magnetostrictive Thin Films

This paper presents a bidirectional optimization method on a wireless microswimming robot. The robot is developed based on fin beating propulsion employing two giant magnetostrictive thin films for left and right fins. An innovative drive approach, using separate second-stage resonance frequencies of the left and right fins to generate right and left thrusts, is proposed and implemented on a bidirectional microswimming robot prototype. Dynamic model of the proposed microrobot has been derived based on theoretical analysis. A discrete variate method for optimizing left fin configuration is proposed under the constraints of fixed surface area and sufficient fin end strength, and a genetic algorithms method for optimizing right fin configuration is employed under constraints of symmetry and linearity of bidirectional swimming. Simulation and experimental results have demonstrated that bidirectional swimming performance of the robot is greatly improved with low driving frequency and a large range of swimming speed in both directions.